package com.fengjue.config;

import com.fengjue.config.security.JwtTokenUtil;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageChannel;
import org.springframework.messaging.MessageHandler;
import org.springframework.messaging.simp.config.ChannelRegistration;
import org.springframework.messaging.simp.config.MessageBrokerRegistry;
import org.springframework.messaging.simp.stomp.StompCommand;
import org.springframework.messaging.simp.stomp.StompHeaderAccessor;
import org.springframework.messaging.support.ChannelInterceptor;
import org.springframework.messaging.support.MessageHeaderAccessor;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.util.StringUtils;
import org.springframework.web.socket.config.annotation.EnableWebSocketMessageBroker;
import org.springframework.web.socket.config.annotation.StompEndpointRegistry;
import org.springframework.web.socket.config.annotation.WebSocketMessageBrokerConfigurer;

@Configuration
@EnableWebSocketMessageBroker
public class WebSocketConfig implements WebSocketMessageBrokerConfigurer {


    @Value("${jwt.tokenHead}")
    private String tokenHead;

    @Autowired
    private JwtTokenUtil jwtTokenUtil;

    @Autowired
    private UserDetailsService userDetailsService;


    /**
     * 添加端点 endpoint，这样在网页里可以通过websocket连接
     * 指定websocket服务地址，是否启用socketJS
     * @param registry
     */
    /**
     * 客户端连接我们
     *
     * @param registry
     */
    @Override
    public void registerStompEndpoints(StompEndpointRegistry registry) {

        registry
                //  /ws/ep 注册为stomp的端点，用户连接这个端点就可以进行websocket通讯
                .addEndpoint("/ws/ep")
                // 允许跨域
                .setAllowedOrigins("*")
                // 允许 socketJS
                .withSockJS();

    }

    /**
     * 输入通道参数配置
     * <p>
     * 获取 JWT 令牌
     *
     * @param registration
     */
    @Override
    public void configureClientInboundChannel(ChannelRegistration registration) {
        registration.interceptors(
                new ChannelInterceptor() {
                    @Override
                    public Message<?> preSend(Message<?> message, MessageChannel channel) {
                        StompHeaderAccessor accessor = MessageHeaderAccessor.getAccessor(message, StompHeaderAccessor.class);
                        // 判断accessor是不是 链接，如果是，获取token ，并且设置用户对象
                        if (StompCommand.CONNECT.equals(accessor.getCommand())) {
                            String token = accessor.getFirstNativeHeader("Auth-Token");
                            if (!StringUtils.isEmpty(token)) {
                                String authToken = token.substring(tokenHead.length());
                                String username = jwtTokenUtil.getUserNameFromToken(authToken);
                                // token中存在用户名
                                if (!StringUtils.isEmpty(username)) {
                                    // 登录
                                    UserDetails userDetails = userDetailsService.loadUserByUsername(username);
                                    // 验证token是否有效，如果有效，重新设置用户对象
                                    if (jwtTokenUtil.validateToken(authToken, userDetails)) {
                                        UsernamePasswordAuthenticationToken authenticationToken = new UsernamePasswordAuthenticationToken(userDetails, null, userDetails.getAuthorities());
                                        SecurityContextHolder.getContext().setAuthentication(authenticationToken);
                                        accessor.setUser(authenticationToken);
                                    }
                                }
                            }
                        }
                        return message;
                    }
                }
        );

    }

    /**
     * 我们向客户端发消息，客户端通过/queue接收消息
     * <p>
     * 配置消息代理
     *
     * @param registry
     */
    @Override
    public void configureMessageBroker(MessageBrokerRegistry registry) {
        // 配置代理域吗，可以配置多个，配置代理目的地前缀为 /queue,可以在配置域上向客户端推送消息
        registry.enableSimpleBroker("/queue");

    }
}
